Diffuser head



D. ROSS ETAL DIFFUSER HEAD June 1, 1965 2 Sheets-Sheet 1 Filed Feb. 6,1963 INVENTORS .34 W0 5'. Pass ATTORNEY5 June 1, 1965 D. 5. R058 ETAL3,186,544

DIFFUSER HEAD Filed Feb. 6, 1965 2 Sheets-Sheet 2 INVENTORS ar/0 5. FossBY 65/115 M Foss M "Mun United States;

3,136,644 I DKFFUSER HEAD David S. Ross and Gene W. Ross, Lorain,(lihio, assignors to The Amcodyne Corporation, Lorain, (lhio, acorporation of Delaware Filed Feb. 6, 1963, Ser. No. 256,735 11 Claims.(U1. 239-534) This invention generally relates to a diffuser head andmore particularly to a diifuser head wherein gas, typically air, issupplied under pressure and passes into a liquid through orificesprovided in the walls of the diffuser head.

Such diifuser heads are of particular utility in the treat ment ofsewage, ore flotation processes, treatment of industrial wastes, variousfermentation processes and certainchemical processes where gas-liquidcontact is essential.

Frequent clogging ofthe orifices of the diffuser head is experienced,particularly in the aeration of sewage, when the air supply is cut off,and the surrounding liquid backfiows through the orifices, carrying withit hits of debris that are not removed when the flow of air is resumed.Thus, frequent and expensive maintenance was required to unclog theorifices or to replace the diffuser head.

Heretofore attempts to provide a diffuser head which will resist thisclogging have not been completely satisfactory and resulted inrelatively cumbersome and expensive devices which were unable to endureextended and repeated use.

Therefore, the principal object of the presentinvention relates to anovel diffuser head of simplified construction, the orifices of whichwill not clog due to debris carrying backflow when the air supply is cutoff.

A further object of this invention relates to a novel diffuser head ofsimplified construction which resists clogging and will endureextended'and repeated use.

Other objects and the entire scope of the present invention will becomeapparent from the following detailed description and by reference to theaccompanying drawings. It should be understood, however, that thedetailed description and specific examples while indicating preferredembodiments of the invention, are given by way of illustration only,since various changes and modifications within the spirit and scope ofthe invention will become apparent as the description herein progresses.

Reference is made to the accompanying drawings which form a part hereof.

FIGURE 1 is a fragmentary perspective view partly in section showingadiifuser head constructed in accordance with our invention;

FEGURE 2 is a perspective iew of our novel diifuser head with interioroperating pressure applied thereto;

, iighfid .Patented June l, 19%5 section showing a further modificationof our invention;

' and 7 FIGURE 10 is a view in section taken along the line.

ie-rs of FIGURE 8.

In the drawing numeral 1 generally indicates one form of a diffuser headconstructed in accordance with our in vention.

As shown in FIGURE '1, the diffuser head generally comprises a hollowcore 2 of metal or other suitable material and an expansible resilientcover or sleeve 3 of rubber or other suitable elastomeric material suchas plastic.

The core 2 is provided with a plurality of perforations or orifices Sfor the passage of a gas, typically air, from the inside of the core tothe interior of the sleeve 3. One end of the core is blanked by a cap 4or by other suitable means.

The sleeve 3 is provided with a plurality of normally closed slits 6which extend through the thickness of the sleeve.

As best seen in FIGURE 1, the sleeve 3 is adapted to receive the core 2with the slits 6 remainingin their normally closed condition. The endportions of the sleeve 3, adjacent the end of the core 2, must be insealing engage ment therewith. This seal may readily be effected by anysuitable. means, such as by means of the clamp 8 shown in FIGURE 1.Other means of effecting such a seal will be apparent to those skilledin the art.

When the core 2 and sleeve 3 are assembled in operative relation to formour novel diffuser head shown in FIGURE 1, and diffusing gas pressure issupplied to the diffuser head, it is readily seen that the gas will passthrough the orifices 5 into the interior of sleeve 3 and thus cause thesleeve to resiliently distend or expand.

The distention of the sleeve 3 will cause the slits 6 to open, as shownin FIGURE 2, and thus permit the passage of gas therethrough.

When the diffusing gas pressure is cut off the sleeve 3 will no, longerbe acted upon by the interior expanding pressure. As a result, thesleeve 3 will contract and return to its normal unexpanded condition andsimultaneous therewith the slits will close, and return'to theirnormally closed condition.

It is readily seen that debris-carrying baclcfiow is eifec tivelyprevented since the orifices of the diffuser head are FIGURE 3 is afragmentary perspective view of the closed whenever there is no positivediifusing gas pressure. Thus, clogging of the orifices by debris carriedby the backflow when the diffusing pressure is cut oif, is prevented.

When the aforementioned embodiment has been effective, it .has beenfound that duringextended use, where the resilient sleeve undergoesrepeated distentions and contractions, there is a tendency for the slitsto enlarge or elongate as a result-of a tearing at their end portions,as indicated at 9 in FIGURE 3. The elongation of the slits results fromthe expansion of the sleeve at the end portions of the slits. Thisenlargement of the slits will shorten the useful life of the sleeve andnecessitate relatively frequent replacement thereof.

The problemof slit enlargement isparticularly acute the increased.pressure differential tending to expand the 7 head which tends torestrain expansion of the sleeve. The. expensive alternatives of cuttingoff the supply of difiusing" gas to all the difiuser heads in ordertomerely remove one i wall thickness of the sleeve adjacent the. ends ofeach slit. In FIGURES 8 and '10 the thickened wall portionsof the sleevewhich functionas means: to preventslitv en largement are 'seen tocomprise a plurality ofcontinuous from the treatment tank orinstallingindividual cut-off sleeve or alternatively the sleeve itself maybeprovided with a thickened restraining portion adjacent the ends of eachslit.

FIGURES 4, and 6 show embodiments of our novel diffuser head providedwith means to prevent slit enlargement, such means being in the .form oftape.

In FIGURE 4, it will be seen that the sleeve is provided with aplurality of slits'arranged in generally parallel rows or hands, spacedlongitudinally of, and along the periphery of the sleeve 3. A suitabletape ltl has been adhered to the sleeve 3 at the end of each slit andforms.

parallel bands intermediate each row of slits. In the illustratedembodiment the tape is of sufiicient width'to extend from the ends'ofthe slits in tone peripheral row to the opposing ends of the slits inthe adjacent peripheral row. If it is desired to utilize a tapethat isnarrower than the distance between adjacent rows of slits, a separatelength of tape for the ends of the slits in each row may be employed.

FIGURES illustrates slit enlargement when the slits 6 are arranged inparallel spiral rows about the periphery of the sleeve 3. Tape 19 hasbeen adhered to the sleeve 3 at the end of each slit 6 and forms aspiral band about the periphery'of sleeve 3 intermediate the adjacentspiral rows of slits.

*As pointed out above, separate lengths of tape for the ends of each rowof slits may beemployed if a tape, narrower than the distance betweenadjacent rows of slits is utilized.

ment small sections of tape it are adhered adjacent the end of each slit6 rather than a continuous length of tape being adhered adjacent theends of several slits as in the aforementioned embodiments. It isreadily seen that this modification may advantageously be employed wherethe particular slit pattern does not readily lenditself to theapplication of continuous lengths of tape.

FIGURE 7 illustrates a further modification of the use of tape; 10 toprevent slit enlargement. In thisembodimerit a suitable length of tape10 is placed directly and completely over a plurality of slits andadhered to the immediately adjacent surface portions of thesleeve. Theportions of the tape that immediately overlie the slits are thencut'outorjremoved asat 11 to provide apertures exposing the slits 6,'with thetape adhered adjacent each end of each slit. While in the aforedescribedembodiment the portions of the tape overlying the slits were removedafter the tape had been adhered to the sleeve, it is apparent that tapehaving pro-cut apertureslocated 7 'so as to registerwith the slits mightreadily be employedx This modification lends'itself to rapid andeffective applicationrofthe tape to the sleeve as] well as providing aneliective means forpreventing slit enlargement.

FIGURES 8, 9 and 10 show a further modification of our novel diffuserhead provided With meansto prevent slit enlargement, such meanscomprising an increased the use of' tape ltl to preventelliptical raisedportions 12 whichform crater-like projections laterally enclosingeachslit 6; Thus itj will be noted that adjacent the ends or" each slitthe Wall of the sleeve is provided with thickened portions which preventslit enlargement.

FIGURE ,9 illustrates a modification wherein the thickened wall portionsof the sleeve 3 arein the form of continuous circumferential bands or.ribs 14 located at the ends of each slit 6. It will "be readily apparentthat the thickened wall portions of the sleeve may assume many'otherconfigurations and is not'to be limited to those nowv shownanddescribed. The aforementioned modification is of particular utility fromthe point of view of ease of manufacture since the thickened built-upwall portions of the sleeve may readily, beformed or molded 7 duringthe. formation of the sleeve.

While in the above examples the slits are shown to extend longitudinallyof the sleeve it is clear that the slits may extend in other directionsrelative to the longitudinal axis of the sleeve, in which case tapemaybe suitably positioned and adhered adjacent theends of each slit, orsuitably located thickened wall portions may be provided in the sleeve.

The, present invention will thus be seen to completely and effectivelyaccomplish the objects enumerated hereinabove. 'By providingadittuserhead of our novel construction, clogging. of the orifices, dueto debris carrying V backllow is completely eliminated. Moreover, ourdiffuser head is of a simplified construction thus facilitatingmanufacture and at the same time'is durable and able to withstandextended use with a minimum of maintenance.

ciples ofthis invention, without. departing from these principles.Therefore, while the present invention has been described withparticular reference to the specific forms shown in the drawings, it istobe understood that such is not to be construed as imparting anylimitations upon this invention; which includes all modificationsencompassed within the spirit and scope of the following appendedclaims.

What is claimed is:- r p l. A ditfuser head comprising, in combination,a per-.- forated hollow core adapted to freceive gas under .pressure, aresilientsleeve receiving said. hollow core, said sleevebeing adapted todistend'under said air pressure, a plurality of'slits in said sleeve,the opposed wall surfaces of each of said slits being in intimatecontiguous sealing engagement when said resilient sleeve is in a relaxedconditiomand tape means adhered to said sleeve'adjacent the ends of theslits to restrainexpansion of the sleeve at, the end portions of saidslits:

I 2.. Adiffusenhead as set forth in claiml wherein said diffuserheadincludes'means for sealing said core'within said sleeve.

3. A difi userhead asset forthjin claim 1 wherein said jacent rows ofslits.-

5. A ditiuserzhead as setforth in claim 1 wherein'said slits arearranged in longitudinallyspaced and-parallel spiral rows 6.. A diffuserhead as set forth in claim 5 wherein said.

tape means. is arranged in longitudinally spaced parallel rowsintermediate said rows .of. slits.- a

7. A resilient sleeve adapted to receive the multiperforated hollow coreof a diifuser head, said sleeve being further adapted to.expandunderiinterior gas pressure, a

8. A resilient sleeve as set forth in claim 7 wherein said slits arearranged in parallel rows spaced longitudinally of the sleeve.

9. A resilient sleeve as set forth in claim 8 wherein said tape means isarranged in parallel bands intermediate adjacent rows of slits.

10. A resilient sleeve as set forth in claim 7 wherein said slits arearranged in longitudinally spaced and parallel spiral rows.

11. A resilient sleeve as set forth in claim 10 wherein said tape meansis arranged in longitudinally spaced parallel rows intermediate saidrows of slits.

References Cited by the Examiner UNITED STATES PATENTS 2,255,438 9/ 41Robinson 239-534 2,952,413 9/60 Jepson 239602 FOREIGN PATENTS 916,249 85 4 Germany.

LOUIS I. DEMBO,Primary Examiner.

EVERETT W. KIRBY, Examiner.

1. A DIFFUSER HEAD COMPRISING, IN COMBINATION, A PERFORATED HOLLOW COREADAPTED TO RECEIVE GAS UNDER PRESSURE, A RESILIENT SLEEVE RECEIVING SAIDHOLLOW CORE, SAID SLEEVE BEING ADAPTED TO DISTEND UNDER SAID AIRPRESSURE, A PLURALITY OF SLITS IN SAID SLEEVE, THE OPPOSED WALL SURFACESOF EACH OF SAID SLITS BEING IN INTIMATE CONTIGUOUS SEALING ENGAGEMENTWHEN SAID RESILIENT SLEEVE IS IN A RELAXED CONDITION, AND TAPE MEANSADHERED TO SAID SLEEVE ADJACENT THE ENDS OF THE SLITS TO RESTRAINEXPANSION OF THE SLEEVE AT THE END PORTIONS OF SAID SLITS.